In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

207Genetical Studies for Conservationof Tropical Timber Species in IndonesiaULFAH J. SIREGARFaculty of Forestry, Bogor Agricultural UniversityKAMPUS IPB DARMAGAPO Box 168, Bogor 16001, Indonesiaucregar@indo.net.idAbstract. As deforestation in Indonesia continues at an alarming rate, sustainable forestmanagement and conservation of forest genetic resources have become very important issues.Most conservation programs in Indonesia, however, are usually based on ecological information,and rarely consider genetic aspects. Population genetic studies of some commercial timberspecies, consisting two dipterocarp species and one non-dipterocarp species in CentralKalimantan, showed that the species are one large panmictic population. Some disturbance suchas logging would not immediately reduce the genetic diversity of the species but has, however,induced the disturbed populations to differentiate from the original ones, and reduced theoutcrossing rates. Reduced genetic diversity has been observed in a completely isolated populationof a mangrove species in Jawa, which was formed due to extensive development of the mangrovearea leading to fragmented populations. Efforts to conserve those species in situ should bedirected toward restoring the disturbed populations to resemble the original, panmictic ones,whereas ex situ conservation should attempt to collect as large as possible gene pools in thepopulations to maintain the outcrossing nature of most tropical timber species. Other importantfactors to be considered in designing an ex situ conservation program or a seed orchard, as shownby a study on pine, are a balanced ratio among alleles, and presence of assortative or preferentialmatings among individuals collected. Those factors would ensure that most individuals sampledwill produce seeds for subsequent generations.IntroductionEvery year the world loses about 15 – 17 million hectares of forests andthousands of species, and most modern deforestation is happening in tropicalareas (Blaser & Douglas 2000, Contreras-Hermosilla 2000). The World Bankestimated rates of deforestation in Indonesia between 263,000 to 1,315,000 haper year (Sunderlin & Resosudarmo 1996). The primary causes of deforestationare human activities, which exploit forests in unsustainable ways in search ofprofits and means of subsistence. Although forest products are recognized asthe biggest source of government income besides oil and gas, the cost to societyfrom deforestation and forest degradation is often considered to exceed thebenefits (Contreras-Hermosilla 2000).Acute deforestation and forest decline have generated a strong callfor conservation of forest ecosystems and genetic resources. In theory, forest